1. Field of the Invention
The present invention relates to an automatic storage and retrieval system of pallets for handling of work pieces.
2. Description of the Related Art
As is well known, in automatic flexible manufacturing systems (FMS), various loading stations are used, by means of which work pieces located e.g. on a pallet are supplied to the system for machining, storing or another handling. Typically, the system comprises various automatic lift and transfer devices, which, by means of the FMS control system transfer work pieces according to a predetermined or dynamic instruction to different machine tools or devices treating the work piece. The transfer between a shelving system and one or more machine tools is typically conducted by means of lift and transfer devices. The transfer device typically comprises a stacker crane or a transfer carriage, which, for example by means of telescopic forks manipulates the work piece with its base.
In the loading station the work piece arriving in the system and the pallet of the same are received and transferred to a storage rack from which it is transferred forward to the machine tool at the right moment. The control program of the control system contains the manufacturing instructions of each work piece stored therein and the system is connected to the loading station, transfer device and machine tool to transfer the desired work piece in the correct order to the desired one or more machine tools and the control program transmits information to the machine tool so that the desired machining program can be selected. When the work piece is delivered to the loading station, information thereof is at the same time inputted to the control system. Typically the machine tool also contains an intermediate station to which the work piece is delivered. Finished or semi-finished work piece is returned to the storage rack and it can be delivered later via the loading station. In the loading station the piece can be manipulated manually as well as by means of a forklift truck or a crane.
The act of building a shelving and the installation, assembly and test-drive of the transfer carriage in the location of delivery require expert knowledge, and the work takes 150 to 250 hours even in connection with small-scale deliveries. Especially the fastening and support of the shelving and the guiding rails of the transfer carriage to the floor surfaces require a great deal of work and preparations. In addition to this, the control system must be tested on location and for example the final, exact location of the storage locations in the shelving systems must be taught separately to the control system of the transfer carriage after installation. Thus, the installation and testing processes require a great deal of time during which rearrangements interrupt or disturb the production for a long period of time. The installation project consumes employee resources considerably in a company in which the system has been acquired.
It is an aim of the present invention to considerably reduce the time used for installation and test-drive of the FMS system at the location of installation. In particular, it is an aim of the invention to utilize an integrated system to facilitate the implementation of a shelving, a transfer carriage and a control system and, if necessary, also the implementation of loading stations. The integrated system which is tested in advance and programmed ready for use according to the wishes of the customer, can be rapidly connected to machine tools at the location of installation to produce a complete FMS system. The invention is based on the idea that a rapidly implemented integrated system is arranged into a movable module, for example to a standard transfer container.
It is a considerable advantage of the invention that the amount of installation work required at the location of installation can be reduced even into one tenth of the work typically required therein. The installation work itself at the location of delivery is also considerably facilitated, and special personnel is not required therein. It is possible to abandon the packing and unpacking of individual parts of the system, as the system is transported in a ready-for-use state. The number of fastenings required for fixing the system to the floor is considerably reduced, wherein transfers and changes are possible at a later stage without dismounting the entire system. The structure itself to which the system is placed operates as a support structure and a protective structure for the system, which prevents the access of unauthorized persons to the working area of the transfer device. Working safety during installation is considerably increased. The movable container is also provided with the necessary openings that can be closed, via which openings the transfer carriage can deliver the work piece to a machine tool or to the loading station.
The module also contains a control system which can be taken in use almost immediately, because it has undergone a test-drive and a test during the manufacture of the module itself. Thus, it is possible to provide the control system in advance with manufacturing instructions for the manufacture of different pieces, when the machine tools at the location of delivery are known. The advantage lies in that said modules can be produced in series for the needs of the client. The movable module only requires an input coupling for electricity, as well as electric data transmission connections and interfaces for connecting the module to the machine tools and loading stations of the FMS system.
A special advantage is that the module can be expanded. Thus, behind the first module which comprises at least a control system, a shelving and a transfer carriage, a second module is connected, which comprises at least a shelving and an extension rail arrangement for the transfer carriage. The number of storing locations can thus be increased. The assembly of one or several modules constitutes an automated pallet storage and retrieval system. By providing the module with a removable roof, the height in use in the storing locations can be increased.
It is an advantage that the system is also well suited for temporary production and it can be moved rapidly to another location. By placing the loading station in such a manner that it travels along with the system as well, it is possible to ensure compatibility and the installation work becomes easier and easier. During transport, the loading station is stored inside a freight container, from which it is lifted out and installed in its place on the side of the freight container. The module can also be transferred easily by means of devices used in goods yards or for example in harbours, when a freight container with standard dimensions is used, which also comprises fixing means for example for container cranes.